Large Gems are items designed for the PvP game Capture the Gem, and are dropped when the player dies, even if they are in Softcore mode. With each different Large Gem that is held or carried in the player's inventory, a hologram of it appears above the player's head. If two or more different Large Gems are carried, their holograms will revolve in a circular pattern above the player's head. They are immediately deleted if placed in a player's Trash Can.
Large Gems can also be placed into a Gem Lock, functioning as a key. This can prove valuable within the makings of adventure maps.